/*
- * Copyright 2015 Facebook, Inc.
+ * Copyright 2016 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
*
*/
-#ifndef FOLLY_ATOMICHASHMAP_H_
+#pragma once
#define FOLLY_ATOMICHASHMAP_H_
#include <boost/iterator/iterator_facade.hpp>
{}
};
-template<class KeyT, class ValueT,
- class HashFcn, class EqualFcn, class Allocator>
+template<class KeyT, class ValueT, class HashFcn, class EqualFcn,
+ class Allocator, class ProbeFcn, class KeyConvertFcn>
class AtomicHashMap : boost::noncopyable {
- typedef AtomicHashArray<KeyT, ValueT, HashFcn, EqualFcn, Allocator> SubMap;
+typedef AtomicHashArray<KeyT, ValueT, HashFcn, EqualFcn,
+ Allocator, ProbeFcn, KeyConvertFcn>
+ SubMap;
public:
typedef KeyT key_type;
typedef std::pair<const KeyT, ValueT> value_type;
typedef HashFcn hasher;
typedef EqualFcn key_equal;
+ typedef KeyConvertFcn key_convert;
typedef value_type* pointer;
typedef value_type& reference;
typedef const value_type& const_reference;
// The constructor takes a finalSizeEst which is the optimal
// number of elements to maximize space utilization and performance,
// and a Config object to specify more advanced options.
- static const Config defaultConfig;
- explicit AtomicHashMap(size_t finalSizeEst, const Config& = defaultConfig);
+ explicit AtomicHashMap(size_t finalSizeEst, const Config& c = Config());
~AtomicHashMap() {
const int numMaps = numMapsAllocated_.load(std::memory_order_relaxed);
key_equal key_eq() const { return key_equal(); }
hasher hash_function() const { return hasher(); }
- // TODO: emplace() support would be nice.
-
/*
* insert --
*
* AtomicHashMapFullError is thrown.
*/
std::pair<iterator,bool> insert(const value_type& r) {
- return insert(r.first, r.second);
+ return emplace(r.first, r.second);
+ }
+ std::pair<iterator,bool> insert(key_type k, const mapped_type& v) {
+ return emplace(k, v);
}
- std::pair<iterator,bool> insert(key_type k, const mapped_type& v);
std::pair<iterator,bool> insert(value_type&& r) {
- return insert(r.first, std::move(r.second));
+ return emplace(r.first, std::move(r.second));
+ }
+ std::pair<iterator,bool> insert(key_type k, mapped_type&& v) {
+ return emplace(k, std::move(v));
}
- std::pair<iterator,bool> insert(key_type k, mapped_type&& v);
+
+ /*
+ * emplace --
+ *
+ * Same contract as insert(), but performs in-place construction
+ * of the value type using the specified arguments.
+ *
+ * Also, like find(), this method optionally allows 'key_in' to have a type
+ * different from that stored in the table; see find(). If and only if no
+ * equal key is already present, this method converts 'key_in' to a key of
+ * type KeyT using the provided LookupKeyToKeyFcn.
+ */
+ template <typename LookupKeyT = key_type,
+ typename LookupHashFcn = hasher,
+ typename LookupEqualFcn = key_equal,
+ typename LookupKeyToKeyFcn = key_convert,
+ typename... ArgTs>
+ std::pair<iterator,bool> emplace(LookupKeyT k, ArgTs&&... vCtorArg);
/*
* find --
*
- * Returns an iterator into the map.
+ * Returns the iterator to the element if found, otherwise end().
+ *
+ * As an optional feature, the type of the key to look up (LookupKeyT) is
+ * allowed to be different from the type of keys actually stored (KeyT).
*
- * If the key is not found, returns end().
+ * This enables use cases where materializing the key is costly and usually
+ * redudant, e.g., canonicalizing/interning a set of strings and being able
+ * to look up by StringPiece. To use this feature, LookupHashFcn must take
+ * a LookupKeyT, and LookupEqualFcn must take KeyT and LookupKeyT as first
+ * and second parameter, respectively.
+ *
+ * See folly/test/ArrayHashMapTest.cpp for sample usage.
*/
- iterator find(key_type k);
- const_iterator find(key_type k) const;
+ template <typename LookupKeyT = key_type,
+ typename LookupHashFcn = hasher,
+ typename LookupEqualFcn = key_equal>
+ iterator find(LookupKeyT k);
+
+ template <typename LookupKeyT = key_type,
+ typename LookupHashFcn = hasher,
+ typename LookupEqualFcn = key_equal>
+ const_iterator find(LookupKeyT k) const;
/*
* erase --
SimpleRetT() = default;
};
- template <class T>
- SimpleRetT insertInternal(KeyT key, T&& value);
+ template <typename LookupKeyT = key_type,
+ typename LookupHashFcn = hasher,
+ typename LookupEqualFcn = key_equal,
+ typename LookupKeyToKeyFcn = key_convert,
+ typename... ArgTs>
+ SimpleRetT insertInternal(LookupKeyT key, ArgTs&&... value);
- SimpleRetT findInternal(const KeyT k) const;
+ template <typename LookupKeyT = key_type,
+ typename LookupHashFcn = hasher,
+ typename LookupEqualFcn = key_equal>
+ SimpleRetT findInternal(const LookupKeyT k) const;
SimpleRetT findAtInternal(uint32_t idx) const;
}; // AtomicHashMap
+template <class KeyT,
+ class ValueT,
+ class HashFcn = std::hash<KeyT>,
+ class EqualFcn = std::equal_to<KeyT>,
+ class Allocator = std::allocator<char>>
+using QuadraticProbingAtomicHashMap =
+ AtomicHashMap<KeyT,
+ ValueT,
+ HashFcn,
+ EqualFcn,
+ Allocator,
+ AtomicHashArrayQuadraticProbeFcn>;
} // namespace folly
#include <folly/AtomicHashMap-inl.h>
-
-#endif // FOLLY_ATOMICHASHMAP_H_
projects / folly.git / blobdiff